Method of forming fibre container bodies



Oct. 25, 1966 s. F. JENSEN METHOD OF FORMING FIBRE CONTAINER BODIES Filed Nov. 21, 1963 5 Sheets-Sheet l BY JTTUIQ/VFV Oct. 25, 1966 s. F. JENSEN 3,280,708

METHOD OF FORMING FIBRE CONTAINER BODIES Filed Nov. 21, 1963 5 Sheets-Sheet 2 Q saw/my WMEXZWAM syfife fi' Oct. 25, 1966 s. F. JENSEN METHOD OF FORMING FIBRE CONTAINER BODIES Filed Nov. 21, 1963 5 Sheets-Sheet 5 United States Patent 3,280,708 METHOD OF FORMING FIBRE CONTAINER BODIES Stephen Frederick Jensen, New York, N.Y., assignor to American Can Company, New York, N.Y., a corporation of New Jersey Filed Nov. 21, 1963, Ser. No. 325,319 4 Claims. (CI. 93-94) The present invention relates to the treating of fibrecontainer bodies and more particularly to a method of artificially aging fibre container bodies to effect a rapid migration throughout the fibre body stock of the liquid component of the water-based adhesive which is used to bond the various body plies together.

Heretofore, in the manufacture of multi-ply fibre container bodies or tubes wherein the plies are bonded together by means of a water-based adhesive, it has been found desirable to store the newly made bodies for periods of from twelve to twenty-four hours after their formation in order to permit the aqueous component of the water-based adhesive to migrate normally throughout the body plies.

This storing procedure was found desirable because the newly made bodies were found to be so soft that they had a tendency to collapse if they were subjected to flanging and/ or end seaming operations in a shorter period of time after their manufacture, the reason for this softness being that the concentration of water in the adhesive so saturated the body plies adjacent the bonded areas that the strength of the body was adversely affected.

By storing the bodies at room temperature for a substantial period of time after the formation of the bodies, the water in these saturated areas was permitted to migrate throughout the bodies, so that although the average moisture content of all of the fibre stock in the bodies stayed constant, the concentration of water in the saturated areas was greatly reduced with the consequent stiffening of the bodies. Since mos-t of the bodies made today have their inner and outer surfaces covered with moisture and Waterproof layers such as aluminum foil, substantially all of the migrating water remains in the body, the loss through the raw circumferential cut edges of the bodies being inconsequential. It is also believed that the migration of Water from the saturated areas effects the setting of the water-based adhesive, thereby imparting additional hardness to the bodies.

This lengthy storage period is very undesirable, however, since it requires considerable storage area, and entails extra body handling operations.

The present invention contemplates the elimination of this lengthy waiting or aging period by providing a body forming method wherein the bodies are heated, substantially immediately after their formation, to a temperature sufficient to heat the water in their interiors to a temperature just below its boiling point in order to speed up the molecular activity of the water and accelerate its migration throughout the fibre body stock. This increase in temperature causes the vapor pressure of the water in the saturated areas to increase, and results in an increased dispersion rate of the water throughout the body plies. It has been found that if the bodies are brought up to this elevated temperature, it is not necessary to maintain them there for any substantial period of time. Instead, they may be immediately withdrawn from the heating chamber and allowed to cool normally to or substantially to room temperature. This cooling operation is effected in a rela tively short time, usually requiring only the time normally required to transfer the bodies from the heating chamber to the body flanging and/ or can seaming machines.

At the completion of this cooling cycle, the bodies have been hardened sufficiently to enable them to withstand the longitudinal pressures of the usual flanging and end seaming operations without collapse.

Thus, all of the advantages of the heretofore lengthy aging operation are attained with substantially no increase in manufacturing time and without the need for body storage facilities and additional body handling operations.

An object of the invention, therefore is the provision of a method of hardening newly formed fibre can bodies preparatory to a flanging or end seaming operation in a minimum of time.

Another object of the invention is the provision of such a method which is eminently adaptable to automatic body manufacturing operations.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings:

FIGURE 1 is a schematic plan view of a portion of a fibre can body line which is adapted to perform the method steps of the instant invention, parts being broken away;

FIG. 2 is an elevational view of the balance of the fibre can body line of FIG. 1;

FIG. 3 is an end elevation taken substantially along the line 33 in FIG. 1; and

FIG. 4 is a cross-sectional View, on a greatly enlarged scale, of a can body of the type which is formed by the instant method.

As a preferred and exemplary embodiment of the instant invention, the drawings show the instant invention as utilized in the manufacture of spirally wound container bodies B which, in the instant embodiment are shown in FIG. 4, as being composed of liner ply 10, which may take the form of a moisture impervious aluminum foil layer which is laminated to a paper backing layer; first and second main body plies 12, 14, preferably made of heavy fiber stock such as kraft or chipboard which is capable of absorbing large amounts of water; and a label ply 16 which is formed of a moisture impervious film of aluminum foil laminated to a paper supporting layer.

The plies 10, 12, 14, 16 are wound together around the mandrel 18 of a conventional spiral winding machine W in the form of endless webs (see FIG. 1). The plies 10, 12, 14 are preferably fed onto the mandrel 18 between its fixed end 20 and an endless winding belt 22 which is wrapped around the mandrel 18 and operates around a drive pulley 24 and an idler pulley 26, the label ply 16 preferably being fed onto the mandrel 18 behind the belt 22 in order to avoid the possibility of scuffing. The pressure of the belt 22 rotates the wound plies and advances them longitudinally along the mandrel 18 in the usual manner.

As they are advanced towards the mandrel 18, a film of a water-based adhesive A is applied to the outer surfaces of the plies 10, 12 and to the inner surface of the ply 16 in order to interpose a film of the adhesive A between the mutually facing surfaces of the various plies 10, 12, 14, 16 and bond them into an integral tube T, the adhesive A being applied by suitable adhesive applying rollers 30, 32, 34 which are supplied from suitable reservoirs (not shown).

The adhesive A may be of any suitable water-basedtype. As an example, the adhesive A may comprise an aqueous solution of dextrine and suitable modifying agents and have a water to solids ratio of about 1 to 1.

Because of the high water content of the adhesive A, much of the water is immediately absorbed into the fibrous stock of the main body layers 12, 14 immediately adjacent the adhesive films, with the result that a portion of these body layers 12, 14 becomes completely saturated with water and becomes extremely soft and soggy. The remaining, non-saturated portions of the body plies 12, 14 retain their rigidity, but-are unable to maintain the initial rigidity of the plies 12, 14 so that as the tube T is initially formed is quite soft and easily deformable.

As a result, it has been found that when such a soft tube is cut into bodies, and the resultant soft bodies are subjected to a flanging and/ or an end seaming operation wherein substantial axial pressures are necessarily imposed upon the bodies, a significant percentage of such bodies frequently collapse or deform and must be discarded. Heretofore, in order to avoid this spoilage, the bodies which were cut from the soft tubes were stored at room temperature in storage periods for from twelve to twenty-four hours in orderv to permit the water in the saturated body ply portions to migratethroughout the body plies and thus substantially reduce the amount of water in the initially saturated body ply portions. While this migration has necessarily increased the water content in the remaining portions of the body plies, since little or no water escapes from the lined and labeled bodies, it has been found that the, resultant bodies become firmer and suffioiently rigid to undergo the flanging and endseaming operations without collapse.

In order to eliminate this storage period by the utilization of the instant invention, the tube T is divided into multibody segments S by a reciprocable cutter knife 38 as it approaches the free end 36 of the mandrel 18, and the segments S are immediately fed into a heating mechanism H.

The cutter knife 38 is carried on and forms a part of the mechanism of the winding machine W and is conventional in nature. It' is preferably indexed with the movement of the tube T so that it moves inwardly into cutting engagement with the tube T at every fourth line L which is provided on the label ply 16 to indicate the line of separation between the individual bodies B. Suitable means for controlling the indexing of the cutter knife 38 are disclosed in United State-s Letters Patent Re. 23,899 and 2,737, 091.

During each cutting operation, the cutter knife 38 moves with the rotating tube T along the mandrel 18, and at the completion of the cutting operation is withdrawn from the tube T and moved backwardly along the mandrel 18 and into position for the succeeding cutting operation.

As the cut, multibody segment S, which in the drawing is shownas containing four bodies B, leaves the end 36 of the mandrel 18, it falls onto a conveyor 40 and is advanced immediately into the heating chamber 42 of the heating mechanism H. The conveyor 40 may be of any suitable type and is here shown as a pair of endless chains 44 which operate around suitable sprockets 46 and are provided with spaced feed lugs 48. If desired, the segments S may ride on tracks 49 which cause them to rotate so that they are heated uniformly within the. heating chamber 42.

The heating chamber 42 contains a suitable number of heating elements 50 which may be of any suitable type, such as direct or infrared burners of any type, heated either by gas or electricity, which are capable of rapidly heating the segments S so that the water which is trapped in the interior thereof is brought to a temperature adjacent to but below its boiling temperature. Care must be taken to avoid overheating of the segments S, since if the water therein is permitted to boil, its rapid expansion will cause blistering of the impervious liner and label plies 10, 16. Preferably, the segments S should be heated to a temperature sufficient to raise the water to a temperature of between 200 to just below 212 F.

The heating chamber 42 need not be any longer than is necessary to heat the segmentsS to their highest desired temperature, since it is not'necessary to maintain the tube at this temperature for any length of time.

Instead, each. segment S, as soon as this desired temperature is reached, is discharged from the chamber 42 into a trough 52 and is pushed onto a mandrel 54 of a cutting machine C by a reciprocable usher. 56. When in position on the mandrel 54, the segment S is rotated by suitable rollers 56 and is subdivided along the lines L into individual bodies B by a moved into contact with the segment S.

At the completion of this subdividing operation, the mandrel 54 containing the cut bodies B'i-s rotated 180 .to discharge position, and the cut bodies B are stripped from it by a re-ciprocable stripper 60 and pushed onto, a discharge conveyor 62 which operates at a faster speed than does the stripper 60 and thus spaces the. bodies B so that they can be turned 90 upon striking a stationary body turning lug 63 and fed into an elevator E (see FIG. 2) which operates as a magazine for a body flanging machine F (see FIG. 2). This elevator E preferably is of the air lift type wherein the cans are propelled upwardly by means of a series of air jets which also function. to cool the bodies to. room temperature. In the flanging machine F, the opposite ends of the bodies B are flanged outwardly in the usual manner by pairs of oppositely disposed flanging dies which simultaneously enter the opposite ends of the bodies from opposite directions and simultaneously form outwardly flaring flanges on both ends of the bodies. These flanging dies, in moving toward each other, exert substantial axial pressures on the bodies B. Next, the flanged bodies are fed into an end seaming machine G (see FIG. 2) by a pair of transfer devices 64. Here, a metal end 65 is applied .to one end of the body B and seamed in position thereon. by suitable seaming rolls 66. Reference may be had to United States Letters Patent 2,633,095 for further details of the body flanging and end seaming operations.

During this seaming operation the body B and end 65 are held in tightly clamped relationship between a seaming chuck 68 and a lifter pad 70 and substantial axial pressures are exerted on the body B. The pressures exerted on the bodies B by the flanging and seaming machines F, G, would normally have been sufficient. to collapse a significant portion of the bodies B had they not been heated in the heating mechanism H. However, because of this heat treatment, the water in the saturated portions of the bodies B is caused to migrate rapidly through the body plies 12, 14, this migration taking place during the time the bodies B travel from the heating mechanism H to the flanging machine F and seaming machine G, so that by the time the bodies B are subjected first to the flanging operation and then to the seaming operation they have stiffened sufiiciently to withstand the axial pressures inherent therein.

As a result, the time consuming and expensive storing operation is made unnecessary, and substantial operating economies are effected.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description and it will be apparent that various changes may be made in the steps of the method described and their order of accomplishment without de parting from the spirit and scope of the invention 01 sacrificing all of its material advantages, the method here inbefore described being merely a preferred embodimen thereof.

I claim:

1. The method of aging a newly formed multilaye' body having its layers secured together by a water-baset adhesive, said layers being of'fibrous material except fo the innermost and outermost layers which are of wate' impervious material comprising heating said body tt bring the temperature of the water in said adhesive tr below its boiling point but high enough to cause it tr migrate throughout thefibrous layers of said body.

2. The method of forming container bodies, compris gang cutter 58 which is.

ing spirally winding a plurality of plies to form them into a tube having a liner ply and label ply of water impervious material and intermediate plies of water pervious fiber material, the mutually facing ply surfaces being secured together by a water based adhesive, cutting said tube into mu-lti-ply body segments, heating said segments to bring the temperature of the water therein to below its boiling point but high enough to cause it to migrate throughout the fibrous plies of said segment, subdividing said segments into individual bodies, and flanging said bodies in a flanging operation wherein said bodies are subjected to axial pressure after said water has migrated sufiiciently to harden said body to withstand said pressure.

3. The method of forming composite containers, comprising forming a spirally wound container body from a plurality of plies the liner and label ply being of water impervious material, the intermediate plies being of fibrous water pervious material, said plies having their mutually facing surfaces bonded together by means of a water-based adhesive, heating said body to bring the temperature of the water in said adhesive to below its boiling point but high enough to cause it to migrate throughout the fibrous plies of said body, and seaming an end onto said body after said water has migrated sufiiciently to enable said body to withstand the axial seaming pressures.

4. The method of forming composite containers, comprising forming a spirally wound container body from a plurality of plies including label and liner p-lies of water impervious material and intermediate plies of water pervious fiber, said plies having their mutually facing surfaces bonded together by means of a water-based adhesive, heating said body to bring the temperature of the Water in said adhesive .to below its boiling point but high enough to cause it to migrate throughout the fibrous plies of said body, and then flanging said body after said water has migrated sufliciently to enable said body to withstand the axial fianging pressure.

References Cited by the Examiner UNITED STATES PATENTS 2,633,095 3/1953 Magill et al. 9339.1 X 3,002,433 10/1961 Dunlap 9394 BERNARD STICKNEY, Primary Examiner. 

2. THE METHOD OF FORMING CONTAINER BODIES, COMPRISING SPIRALLY WINDING A PLURALITY OF PLIES OF FORM THEM INTO A TUBE HAVING A LINER PLY AND LABEL PLY OF WATER IMPERVIOUS MATERIAL AND INTERMEDIATE PLIES OF WATER PERVIOUS FIBER MATERIAL, THE MUTUALLY FACING PLY SURFACES BEING SECURED TOGETHER BY A WATER BASED ADHESIVE, CUTTING SAID TUBE INTO MULTI-PLY BODY SEGMENTS, HEATING SAID SEGMENTS TO BRING THE TEMPERATURE OF THE WATER THEREIN TO BELOW ITS BOILING POINT BUT HIGH ENOUGH TO CAUSE IT TO MIGRATE THROUGHOUT THE FIBROUS PLIES OF SAID SEGMENT, SUBDIVIDING SAID SEGMENTS INTO INDIVIDUAL BODIES, AND FLANGING SAID BODIES IN A FLANGING OPERATION WHEREIN SAID BODIES ARE SUBJECTED TO AXIAL PRESSURE AFTER SAID WATER HAS MIGRATED SUFFICIENTLY TO HARDEN SAID BODY TO WITHSTAND SAID PRESSURE. 